It was at the end of the heat that Sandra Näslund, in the lead, lost her balance and fell. TV footage later showed that Näslund had managed to get back on her feet by herself.
Näslund has been dominant in the skicross world for several years, but was forced to cut short last season due to a knee operation.
In the French Val Thorens, everything seemed normal in the qualifying round, where 28-year-old Näslund was the fastest of all. But then came the mistake that ruined the day for the Swede.
In the men's competition, there were no blue and yellow successes either. David Mobärg was eliminated in the quarterfinals, while his older brother Erik was eliminated in the semifinals.
New World Cup competitions await already on Friday.